Safin was inconsistent in the opening set, dropping serve twice before regaining his rhythm in the second set. The two traded early breaks in the third set before Safin overpowered Chang from the baseline.
His next opponent is Jonas Bjorkman of Sweden, who ousted Argentine Gaston Gaudio, 7-6 (7-2), 6-1.
Ivanisevic, the No. 2 seed, had an easier time with a straight sets victory over 20-year-old Jarkko Nieminen of Finland, 7-6 (7-5), 6-3.
Ivanisevic, the Wimbledon champion,takes on the tournament's youngest player at 19 years and six months, Mikhail Youzhny of Russia. Youzhny defeated Spaniard Albert Montanes on Tuesday, 4-6, 7-6 (6-2), 6-2.
Third seed Jan-Michael Gambill had a short stay in the event following a 6-0, 7-6 (7-3) loss to last year's finalist Francisco Clavet of Spain, the oldest player in the tournament at 33.
Other seeds who advanced were No. 4 Sjeng Schalken of the Netherlands, fifth seed Jiri Novak and No. 6 Greg Rusedski.Schalken beat Galo Blanco of Spain, 6-2, 3-6, 6-3; Novakeliminated Italian Andrea Gaudenzi, 7-5, 6-2; and in a night
match, Rusedski overcame a first set slump to beat Argentine Mariano Zabaleta, 3-6, 6-4, 6-1.
Meanwhile, No. 8 seed and defending champion Dominik Hrbaty of Slovakia lost to qualifier Gilles Elseneer of Belgium in three sets, 3-6, 6-1, 6-2.
Other results on the day saw Michal Tabara of the Czech Republic defeat Brazilian qualifier Andre Sa, 7-5, 6-2; Felix Mantilla of Spain got by Austrain Stefan Koubek, 7-6 (7-5), 6-2; and Argentine David Nalbandian defeated German qualifier Bjorn Phau, 6-4, 4-6, 6-3.